On the progenitor of V838 Monocerotis

We summarize and analyze the available observational data on the progenitor and the enviroment of V838 Mon, the object that erupted in January 2002. We show that the radio and infrared observed matter in the vicinity of V838 Mon could not have its origin in mass loss from V838 Mon but is of interstellar origin. Also from the light echo evolution we conclude that the reflecting dust is of the same nature and not blown by V838 Mon in the past. This is compatible with the photometric data for the progenitor of V838 Mon, from which we exclude the possibility that the object before eruption was an evolved red giant star (AGB or RGB star). We find that most likely it was a main sequence star of ∼ 5− 10M⊙.